Rotary fluid pressure device



Sept. 16, 1941. c. M. KENDRICK 2,255, 81

7 ROTARY FLUID PRESSURE DEVICE Filed March ,28, 1938 5 Sheets-Sheet 1 INVENTOR (WA/H55 M /f END/W671 ATTORNEYS P 1941- c. M. KENDRICK 2,255,781

ROTARY FLUID PRESSURE DEVICE Filed- Marh 28, 1958 3 Sheets-Sheet 2 INVENTOR CW/MLEJ M IfE/VDR/C/f 1 1W5 ATTORNEYS Sept. 16, 1941. c. M. KENDRICK ROTARY FLUID PRESSURE DEVICE 5 Sheets-Sheet 3 Filed March 28, 1938 (f Ti 0 M 2 J M 3 w a n Z 2 7 5 a z zz 3 m 4 5 W W 6 M 2 E w w t INVENTOR (fl/{F455 M/fENDR/C/f M/s ATTORNEYS 1 be n 1s,"19 4i g UNITED .srA'r s PATENT ori ice 1 'no'ranr FLUID mssunn DEVICE Charles m. Kendrick, New York, n. 1., use:

to Manly Corporation, Washingto poration of Delaware Application March raises, Serial No. 19am (cl. rel-s1) I 20 Claims.

This'invention relates to vane type rotary fluid pressure devices and particularly to vane type fluid .motors in which the rotor isprovided with a plurality of vanes arranged to move inwardly and outwardly thereof, for example, ina substantially radialdirection, during the operation of the device. 1 1

Fluid motors of this general class flnd their widest use at present as hydraulic devices, that is,-de vices for handling or whose motive fluid is I a liquid, such, for example, as oil, andthe motor of the present invention will be described in connection with such use. It will be understood, however, thatthe invention is applicable-to motors operating with elastic fluids.

Vane type motors of this character are provantages as radial m ty e pumps, such as low cost, simplicity, compactness, etc. The reason for this is that fluid motors are called upon to operate under conditions not usually encountered by pumps and which previous radial'vane type pumps and motors are incapable of meeting successfully. a fluid motor, for example, is subject to frequent stopping and starting during its vided with avane track which is adapted to con-- tact the exposed ends of thevanesaiidtoguideand control their inward and outwardmcvement. It

is essential that cooperating contact between the varies and the vane track be maintained in or- -der to obtain smooth, duietand satisfactory-operation of the device. 1

In devices of thiskind when operated as pumps,

it is to depend upon, and to utilize the centrifugalforce brought about by the rostarted centrifugal force alone is available to move the vanes outward. In" either case, therefore, the pump does not begin to deliver fluid until the speed of its rotor is suflicient to pro duce the centrifugal force required to eifect some radially outward movement of the vanes. Vane type pumps of this'general class have met with marked commercial success for supplying fluid under pressure to operate the numerous hydraulically actuated devices now in wide industrial use. 'Ihenecessity offrelying on cen-U trifugal'. force to produce outward movement of the vanes has, however, limited their use to applications in which the rotative' speed is suflicient to produce the necessary centrifugal force.

In contrastto the popularity of radial vane type pumps, radial vane type fluid motors have not heretofore been commercially successful, a1- though such motors have many of the same adoperation, whereas a pump is usually kept runwhile in use. A fluid motor must start under full load, which is not required of radial vane type pumps as now employed. A-motor must also operate'underfull load at speeds which never become high as well as in accelerating and decelerating to and fromrelatively high speeds, whereas a'radial'vane typevpumpdoes not begin to op;

er'ate until its rotor ,has attained considerable speed. as already explained. In other wordaa vane type fluid must operate satisfactorily under Jcirc bring about the necessary contact between them and its vane track.

This condition is aggravated in a radial vane type motor, as compared to a radial vane type Dump, because the operating fluid -under operating pressure in contact with the exposed'ends of the moto'rs vanes acts to force them radially inward at the very time these vanes must move radially outward, that is, during intake, which is not the casein such a pump. Introduction of the operating pressure fluid behind the inner ends of the vanes will act to balance the hydraullic force pushing the vanes inward, but results obtained by this expedient are not satisfactory in so far as vane motors are concerned.

Radial vane type motors constructed in the same manner as the usual radial vane type pump 40 either will not start (the fluid merelyby-passing through the motor). or will start with an abrupt jerk. Jerky, noisy and uneven operation continues throughout-the operation of the motor at low rotative speeds, and will continue indefinitely until and unless a speed is reached'at which suiflcient centrifugal force is produced to eifect the necessary contact between the vanes and vane track. This type of operation renders such a vane motor impractical and unsuited for commercial use.

Numerous attempts have been made to overcome this di-fllculty and to provide means for making a radial vane type fluid motor operate satisfactorily.- As far as I am aware, none of these have proved practical or commercially acning continuously and at a relatively hi h speed v inwhich thereisinsumcientcentrifugal force acting on its vanes to of the vanes to urge them outward but limitation of space and other constructional and operating difiiculties have heretofore rendered this scheme impractical.

The :principalobjct of this invention is to overcome the above-mentioned difliculties and 3 provide an improved vane type fluid motor capa- 1 ble of starting smoothly at full load and of operating smoothly and satisfactorily at low rotative speeds at full load as well as at higher speeds. I

Other and more specific objects will appear 1 from the description which follows.

The invention will be understood from a con- '1 sideration of the accompanying drawings which illustrate, by way of example, the invention as 1 embodied in a fluid motor in, which the vanes .move outwardly and inwardly of the rotor in a substantially radial direction.

In the accompanying drawings:

Fig. 1 is a view, partly schematic, showing a side elevation of 'a fluid motor and its connec- 1 tions according to the present invention; Fig. 2' is an enlarged longitudinal sectional 3 view taken through the vertical center line of the motor shown in Fig. 1; Figs. 3 to 7 are sectional views 1 axis of rotation of the rotor drawn to the same 1 scale as Fig. 2 and in which: Fig. 3 is taken along the line 3-3 of Fig. 2

for each revolution of the rotor.

vature is preferably symmetrical on either side of a linepassing through the center of the rotor |5.

Themotor here illustrated is of the hydraulically balanced double acting type of hydraulic device in which each vane is reciprocated twice As shown in I Fig. 3 the space intermediate the periphery of transverse the i 3 lookingin the direction of the arrows, showing Y the rotor and its vanes and other parts of'the j fluid motor; Y

Fig. 4 is a view taken along the line 4l of Fig. 2, corresponding to Fig. 3 but lookingin the opposite direction as indicated by the arrows and 1 showing the rotor side of the cover end plate and 1 cover;

. Fig. 5 is a view along the line 5-5 of Fig. 2, 3 showing the parts as viewed with the cover end plate in place but with the cover removed;

Fig. 6 is a view taken along the line 66 of i Fig. 2 showing the side or face of the casing end i plate, adjacent the a casing; Fig. 7 is a view taken along the line 1-1 of side wall of the cavity inthe v Fig. 2, showing the fluid channels and their cona nections;

Fig. 8 showsa modification of the cover end plate; Fig. 9 is a view, partly schematic, corresponding generally to Fig. l but showing a modifica- Jtion;

Fig. 10 shows a further modification of the invention; and Fig. 11 shows the connections for the insertion of a reversing valve. T- Referring first to the embodiment of the invention illustrated in Figs. 1 to '7 of these drawings, as shown in Fig. 2, the motor includes a casing l0 and cover whichcooperate to form a cavity for the usual rotor 5 and associated ;parts. The rotor I5 is formed with a pair of hubs I6 by which it is rotatably supported in a through the. central bore of the rotor IS, with the'rotor I5 and the vane track 26 is accordingly divided into two fluid sections by means of two sealing areas or chambers formed by cooperation of the rotor l5 and the ends of the vanes l9 with the vane track26 at the region of the vane tracks least diameter, which in this in-: stance is adjacent the horizontal center line. The vane track 26 is preferably provided at each of these points of division (sealing areas or chambers) with a sealing arc 21 substantially concentric with the rotor l5 and extending in a circumferential direction for a distance equal at least to the angular distance between a pair of adjacent vanes I9, in order that there-shall be substantially no radial movement of the vanes is located at the region of the greatest diameter of the wane track 26, and extends circumferentially between the adjacent ends of the inlet and outlet slots 36 and 31, and for an arcuate distance substantially equal to but not less than the distance .between two adjacent vanes l9. Each fluid inlet area 29 is thus at all times radially separated from the =fluid'outlet area 30 of the same fluid section by at least one of the vanes l9 in cooperation with the vane track 26 and the difference in fluid pressure on the opposite side faces of such vanes causes the rotation of the rotor. Fluid is discharged into the outlet slots 31 as the vanes recede from the working spaces.-

The surface of the vane track 26'within the working spaces 3| is preferably concentric with rotor l5 and that intermediate the sealing arcs 2! and the working spaces is given any suitable curvature producing satisfactory rates of inward and outward movement of the vanes l9 as the rotor revolves.

The sides or axial ends of the working spaces, the fluid inlet areas 29 and the fluid outlet areas 3|) are defined by a pair of disc-shaped members 34 and 35. (Fig. 2) for convenience termed end plates? which are provided with holes at their centers through which pass the hubs l6 of the rotor l5. The outer surfaces of the end plates 34 and 35 fit snugly against the adjacent wall.

surfaces of the casing l0 and cover respectively and form substantially fluid tight fits with the several ports and es to be presently de-v scribed. The inner or races of the end plates 34 and 38 form fluid tight flts with the sides of the vane track ring 28 by which they are axially positioned with respect to the rotor I5 in such manner that the rotor is permitted to turn freely while its sides and the sides of the vanes l8 form substantially fluid tight running fits with the adjacent races of the end plates 34 and 35. The end plate 34 will hereinafter be termed the casing end plate" and similarly the end plate 35 will be termed the "cover end plate.

Each of the end plates 34 and 35 is formed with two pairs of arcuate slots 38 and 8! respectively as shown in Figs. 3 to 6.. The slots 36 in the casing end plate 34 serve as the inlet ports for the fluid inlet 28 and the slots 3'! in the same end plate serve as outlet ports for the fluid outlet areas 30. Each slot 38 of the casing end plate 34 and its connected inlet area. forms an inlet chamber and each slot 31 of said casing end plate 34 and its connected area an outlet chamber.

I The fluid circuit of the motor includes a fluid inlet channel 40 (Figs. 2 and 7) and a fluid out-" let channel H. The fluid inlet channel 48 is appropriately connected with a fluid inlet passage or pipe 42 (Figs. 1, 2 and '7) and is also appropriately connected with the fluid inlet ports or slots 38 in the casing end plate 34'as indicated by the dotted "lines oi Fig. '1. The fluid outlet channel 4! is similarly connected with the outlet or discharge pipe, 43 and with the fluid outlet ports or slots 81 in the casing end plate 34.

With theparts in the position shown in Fig. 3, fluid under operating pressure entering the fluid inlet ports 38 will produce clockwise rotation of the rotor and shaft 22. In order for operation to take place, however, it is necessary that the vanes i8 which separate the fluid inlet areas 28 from the fluid outlet/areas 38 at the working spaces 3| be firmly in contact with the vane track and that there be similar contact between the ends of the vanes i8 and the vane track at arcs2'l of-the horizontal points of division between the two fluid sections. It is also important and substantially essentialfor quiet operation that contact between the vanes I8 and thevane track be maintained throughout the movement of the vanes. is through the fluid inlet areas 28, as sudden and abrupt outward movement of the vanes would otherwise result and would produce noise, wear and unsatisfactory operation. But as already explained, this contact of the vanes l8 at the sealing arcs 21 and working spaces 3| and the track-following action of the vanes I8 as they pass through the fluid inlet areas 28 will not dependably result at starting or at low rotative speeds unless the vanes l8 are acted upon by an adequate radially-outward force. According to the present invention, this force is produced and brought to bear on the vanes by improved means for introducing behind the inner ends of the vanes fluid having a controlled pressure higher than that of the fluid in the fluid inlet areas 28. The means employed for this purpose will now be described.

As shown in Figs. 3 to 7, the end plates 34 and 35 are each formed with two pairs of arcuate recesses or grooves 48 and in the races thereof adjacent the rotor 15. These recesses 48 and'48 are positioned to register with the inner ends of the vane slots i8 as the rotor revolves and they act as ports or eways for fluid to and from are so positioned that, as the rotor revolves, they said vane slots i8 and hence are termed vane slot po The vane slot ports 48 .are or such length and register and connect with-the inner end of each vane sloti8 from the'time that the outer end of the vane i 8 therein reaches the point on the sealing arcs 2'! where the vanes l8 act to separate the two fluid sections of the motor. The vane slot ports 48 are coextensive with the fluid inlet areas 28 and conveniently also with the working spaces 3|; that is to say, in this embodiment the vane slot ports connect with the inner end of each vane slot l8 during the time that the vane 18 therein is passing across the corresponding sealing arc 21 through the fluid inlet area 28 and during the entire'time it is traversing the working space.

In order that the vane slot ports 48 may receive a supply of fluid, the vaneslot ports 48 in the cover end plate 35 are connected with the branched ends of a pipe 52, as shown in Figs. 1

and 2. The fluid-connections between each of the vane slot ports 48 in the cover end plate 38 and its branched end of the pipe 52 include a hole drilled through the cover end plate 35 (Figs. 2 and 5)- which connects said vane slot port 48 with a groove!!! (Figs. 2,: 4 and 5) recessed in the outer face or the cover end plate 88, that is, the face adjacent the wall surface of the cover ii. Each groove 58 registers with a passage 8i extending through the cover Ii to which its end of the branched pipe 52 is suitably connected as shown in Fig. 2. In the present embodiment the vane slot ports 48 in the casing end plate 34 are not directly connected with the fluid supply.

although they may be so connected, and act principally as balance ports to contain a supply of fluid (which is received through the vane slots l8) having the same pressure as the fluid in the vane slot ports 48 of the cover end plate 35, in order to substantially balance the hydraulic forces acting on the sides or axial ends of the vanes i8 and prevent binding 01' said vanes.

When the pipe 52 is supplied with fluid having a pressure greater than that of the fluid in the inlet areas 28, such'greater pressure fluid will pass through the intervening fluid connections into the vane slot ports 48 and into all or the vane slots l8 at. the particular instant connected therewith and will force outward against the vane track 28 all of the vanes l8 therein. The pressure of the fluid in the inlet areas depends, however, upon the load, that is, the resistance to rotation presented by the rotor and its connected shaft 22, and this pressure changes as the load changes. The pressure of the fluid in the inlet areas 28 will thus vary through a wide range from a relatively low pressure to maximum, and pressure changes may, and most frequently will, occur suddenly and from time to time during the operation oi the motor. I! the fluid supplied to the vane slot ports 48 was of a constant pressure,.it would therefore be necessary that its pressure at .all times exceed the maximum pressure which might at any time exist in the inlet areas 28. The result of this would be that there would frequently be a very great diiierence between the pressures of the fluid in the vane slot ports 48 and the inlet areas 28, as for example when the motor is operating under light load and the pressure or the fluid in the inlet areas 28 is correspondingly low. For example, if the motor is intended for operation at a maximum pressure of 1,000 lbs. per square men in its fluid inlet areas, the fluid supplied to sure of the fluid in the inlet areas is low, such as 100 lbs. or 200 lbs. per square inch.

This condition is highly undesirable because of the losses involved in raising the pressure of the fluid supplied to the vaneslbt ports 48 to an unnecessarily high amount and also because the vanes IS in all the vane slots 8 at any instant connecting therewith would be pushed out against the vane track 26 with a relatively great force which would create undue gripping action and tendency for the vanes l9 to bind against the vane track 26, and would also result in increased wear of the parts. In'fact, such an arrangement would be impractical whenever the motor is called upon to operate under widely varying loads, as is usually the case, and could be practically used only a in the rare circumstances in which the motors load is substantially constant. In order to overcome this difliculty, the presen invention provides improved means whereby the plished will now be described. Referring to'Fig. 1, the inlet pipe 42 is provided with a valve 60 which inculdes a valve body 6| slidably mounted in the valve bore therein and which is urged inward toward its fully closed position by aspring 62.- The inner end of the valve body 6| is adapted to be acted upon at all times by the pressure of the fluid in the valves fluid receiving port 63 and is accordingly provided with a small stop 65 to prevent its inner end surface from contacting the closed end of the closed position as shown in Fig. l. The outer end of the valve body 6|, which has the same area as the inner end thereof, is similarly adapted to be acted upon by fluid having the same pressure a that in the valves fluid discharging port 64 and the outer end of the valve bore is accordingly connected with said discharging port 64 as by a passage 66 which enters the valve bore at a point which will not be covered when the valve body 6| is in its fully open position.

When operating pressure fluid is admitted to the inlet pipe 42- it passes first to the valves receiving port 63 where it acts upon the inner end of the valve body 6| and raises said valve body 6| against the spring 62. This'movement of the valve body 6| opens the valve 60 and permits pressure fluid to pass into the valves discharging port 64 whence it immediately passes into the outer end of the valve bore and acts upon the outer end of the valve body 6|. Two oppositely vacting forces arethus brought to bear upon the through the bore of the valve 60 of the proper size to create the necessary difference of pressures of-the fluid in the receiving port 83 and discharging port 64 respectively, due to the resistance of 'flow through said orifice, as determined by the spring 62.

As the areas of the inner and outer ends of the valve body 6| are equal, this balancing of forces acting on the'valve body 6| is determined entirely by relative pressures existing in the receiving port 63 and discharging port 64 respectively and is independent of absolute pressures; that is to say, substantially the same diflerence exists in these pressures regardless of the actual amount of pressure in either of said ports. This diiference is therefore maintained substantially constant throughout the entire range of operating pressures. The valve body 6| will also move immediately to compensate for any change in operating conditions, such as variation in the amount of fluid passing into the inlet pipe 42,

change in viscosity of the operating fluid, etc.

The pressure of the fluid in the valves discharging port 64 is, of course, the same as the pressure of the fluid in the inlet areas 29. Thisv diflerence in pressures is maintained under all ,operating conditions. The higher pressure in the valves receiving port 63, and consequently in its \valve bore when said valve body 6| is in its fully v connected portion of the pipe 42, is accordingly termed the fdifierential high pressure. Valve 60 is likewise usually termed a differential pressure valve, but is also sometimes termed a pressure reducing valve.

The pipe 52 is connectedwith the fluid circuit at a point whereit will receive the differential high pressure fluid. As shown in Fig. 1, this connection is made with the portion of the fluid inlet pipe 42 which leads to the valves receiving port 63. The pipe 52 and hence also the vane slot ports 48 thus always receive a supply of the differential high pressure fluid, the pressure differential of which is made suflicient to force out-- ward andv to maintain proper contact between the ends of the vanes IS in all the vane slots I8 which at any instant register with said vane slot ports 48. The inner ends of the vanes |9 are thus supplied with fluid having sufllcient pressure to keep them in proper operating position, and the pressure of this fluid is always definitely related by a relatively constant difference to the pressure of the fluid acting on the exposed ends of the vanes l9. The amount of this pressure differential is determined by the spring 62 and may be varied by adjustment of the screw 61 (Fig. 1). In practice it has been found that a pressure differential of from about 10 lbs. to 75 lbs. per square inch is usually sufficient and may be varied as conditions require but is preferably kept at the minimum.

Another feature of the arrangement shown in Fig. 1 is that it assures proper contact between the ends of the vanes I9 and the vane track 26 before any pressure fluid is admitted to the fluid inlet areas 29 where it can act upon the exposed ends of said vanes. This is due to the fact that the valve body 6| completely cuts off communication between the portions of the pipe 42 which are connected with the receiving port 63 and the spring or, as would be true when the motor .is not in operation. Thus no fluid can pass through the valve. OI until the pressure in its receiving port 83 (and hence in the vane slot ports 48) rises sumciently to lift the valve body I against the spring '2; that is to say. until the diflerential high pressure has been established. The vanes I! will therefore be forced into their proper operating positions a slight time before the operating pressure fluid strikes their outerends in the-inlet areas 29. This is important at starting and assures that the motor will begin tooperate promptly, smoothly and q i tly. v

The operation of the motor is regulated by the amount of pressure fluid admitted to the inlet pipe 41, which may be controlled by any suitable means, not shown. It will be seen from the fore- -tributedtothesucccssandpopularityofvane,

tions and that immediately thereafter operating pressure fluid will act against the exposed ends of the vanes I9 at the arcs II, as. already explained, to produce clockwise rotation of the ro- Up to this point the operating requirementsof the vanes I9 while passing through the outlet areas 30 have not been considered. The ends of the vanes I! are, of course, exposed only to the relatively negligible pressure of the outlet fluid during this portion of their rotary travel.

fact the same parts may be employed without change both for such a pimp and for this motor except for the modifications in the end plates 34 and ll and in the cover II required to supply the differential high pressure fluid to the vane slot ports 4.. A fluid motor constructed according to the present invention therefore enjoys substantially all of the advantages which have cony Pumps for operation at relatively high such as low cost. compactness. simplicity,

cover end plate. In both end plates are provided with a single. annular vane slot port I which continuously connects with all of the vane slots I8. Differential high pressure fluid is supplied to the vane slot port I in the cover end plate I35 in the same manner as in the embodiment shown in Figs. 1 to "I. The cover end plate I3! is accordingly formed with a pair of grooves I50 on its outer face which connect with the vane slot port I by means of a pair of holes drilled through said end plate I35 and which also'register with the fluid passages ii in the cover H to which the ends 0! the branched pipe 52 are connected.

With this arrangement the difierential high pressure fluid is at all times supplied to the inner ends of all the vane slot ports I8 and hence acts continuously throughout their rotation to exert an outward force upon all of the vanes I9. Since the vanes I9 are acted upon by the difierential Upon reference to Fig. 3, it will beseen that the vanes it move inward from the time they of division between the two fluid sections. The n vane track 2' is' alone sufllcient to produce this inward movement of the vanes it but it is necessary to provide means for the escape of fluid contained in the inner ends of the vane slots ll, that is in the portion of the vane slots it radially inward of the inner ends of the vanes I9.

The vane slot ports is inthe end plates 34 and 35 (Figs. 3 to 6) are made of such length and position that they register with each vane slot II during this portion of the rotary travel of the vane I9 therein and each vane slot port 49 is connected with the fluid outlet areas 30 by means of a groove 53 formed in the outer faces of the end plates 34 and 35 and extending to the arcuate slots 31. Fluid is thus'free to pass from the inner ends of the vane slots It to the fluid outlet areas 30. This construction has the advantage of reducing the load imposed upon the vane track 26 by the vanes it during this part of their travel to substantially that resulting from centrifugal action and from the small force necessary to move the vanes I8 radially inward, thus minimizing power losses and wear.

A fluid motor constructed as hereinbefore described and as illustrated inFigs. 1 to 7 -will start promptly and smoothly, will operate evenly and quietly both at relatively low speeds as well as at relatively high speeds. Its parts are simple high pressure fluid while their outer ends are passing through the outlet areas at, the wear and friction on the corresponding portions of the vane track, 25 is greater than with the arrangement of Figs. 1 to 7. The construction of Fig. 8 has the advantage of somewhat greater simplicity of manufacture, however, and will also require a smaller volume ofdifierential pressure fluid as the amount of fluid needed'to flll the inner ends of the vane slots 68 as the vanes I9 therein move outward while passing across the inlet areas is the same as the quantity of fluid simultaneously displaced from the inner ends of outlet areas. The volume of diflferential high and require relatively little change from those suitable for use in a. vane type pump intended for operation at relatively high speeds only. in

pressure fluid therefore need be no more than enough to make up for leakage from the vane slot ports I48 and vans slots. I8.

The arrangement shown in Fig. 9 differs from that ofrFig. 1 only in the means by which the differential high pressure fluid isobtained. The branched pipe I52 is in this instance connected with the discharge port-of a small auxiliary pump I10 which may be driven by any suitable means, not shown, and which is made such that it at all times supplies a, quantity of fluid in excess of the amount required by the vane slot ports 48, or I48, as the case may be. The pipe I52 is also connected by a pipe I54 with the fluid receiving port of a small valve I60 yvhose fluid discharging port is connected by a pipe I55 with the fluid inlet pipe I42.

The valve I60 may be of the same type as the valve 60 of Fig. 1 but is here shown as a pressure relief valve having a spring I62 which urges the ball IGI toward its fully closed position. The

eXceSs fluid not needed by the vane slot ports exhausts through the valve I60 into the pipe I42 .and the valve I50. acts to maintain a differential in the pressures of the fluid in the pipes I42 and I52 respectively which is determined by. the

a spring I52. The pressure of the fluid in the pipe I52 and hence in the'vane slot ports connected therewith is thus definitely related to the pressure of the fluid in the pipe' I42 which-is the same as-the pressure in the fluid inlet areas 29,--and the differential in pressures is continuously maintained.

The-inletprt of I the pump I18 ispreferably connected as by a pipe "I with the fluid inlet pipe I42, so thatv its supply. of fluid has the same pressure asthat of, the fluid in said pipe I42.

would otherwise be required for this purpose.-

Thearrangementof Fig. 9 also has-the advantage of reducing the volume of fluid raised to the differential high pressure level to only a little more than must be supplied to the vane slot ports in order to obtain proper vane action.

This is particularly advantageous when end plates of the type shown in Fig. 8 are used, as

the volume of differential high pressure fluid required by them is very small, as already explained. The embodiment of Fig. 9 operates as a fluid motor inthe same manner as the motor illustrated in Figs. 1 to .7, which has already been explained.

It sometimes may be-desirable to eliminate a speed-responsive mechanism, here shown as a conventional centrifugal governor 1280. The governor 280 includes the usual governor sleeve 28I which moves upward under centrifugal action of the governor and which is operatively connected as by a pivot 282 with a lever 283, one end of which is fulcrumed on a short link, as at 284. The other end of the lever 283 slidably bears against the outer .end of a short rod or plunger 285 which extends through a suitable opening in the closed end of the valve bore and whose other end bears against the valve piston 214. Force exerted by the governor280 in an upward direction upon the governor sleeve 28I therefore tends to move the valve piston 214 against the spring 211. f v

The governor 280 is operated at a, speed hav-f ing a fixedrelation to that of the rotor of the It is accordingly shownas driven through gearing 286 by the driven shaft 222 of the fluid motor which is made .of such length that one end thereof projects through a suitable opening in the motors cover 2.

The force exerted by the spring 211, which may be adjusted by means of the screw 218, is made suflicient to hold the valve piston 214 in its fully closed position when the motor is idle and against the force exerted thereon. by the governor 280 when said govemor 288 is operated at speeds corresponding to the relatively low speeds of the rotary assembly at which centrifugal force alone does not produce satisfactory the differential high pressure fluid after the motor has reached a speed at which the centrifugal action alone is sufllcient to produce satisfactory track-following action of the vanes, as for example, when the motor is to be operated uninterruptedly at such relatively high speeds for a long period. An arrangement by which this is accomplished is illustrated in Fig. 10. It is identical with the embodiment of Fig. 1 except for the provision of-means for by-passing the 3 operating pressure fluid around the valve 60 and the controls therefor.

In this modification the fluid inlet pipe 242 is provided with a by-pass line 212 having its inlet connection with the inlet pipe 242 at a point between the source of operating pressure fluid (not shown) and the valve- 60. The other end of the by-pass line 212 connects with the inlet pipe 242 at a point intermediate the valve 60 and the inlet channel 40 of the fluid motor. Passage of fluid through the by-pass line 212 is con- .trolled by a by-pass valve 213 positioned in said by-pass line 212'and which is-of the conventional hydraulically balanced type. The 'by-pass valve 213includes a balanced valve piston 214 slidable in the bore thereof and provided with axial passages 215 to provide fluid connection between the portions of the valve bore on each end operation of the vanes. Differential high pressure fluid is then supplied to the vaneslot ports 48 through the branched pipe 52 and the motor functions in the same manner as the embodiment of Fig. 1. 1

Increase to relatively high speeds of the driven shaft 222 and of the rotor (at which centrifugal force alone is suflicient to produce satisfactory track-following action of the vanes and diiferential high pressure fluid is therefore not required) will result in corresponding increase in the speed of the governor 280 and of the force exerted by it on the valve piston 214, so that said valve piston 214 will be moved against the spring 211 toward its fully open position. Operating pressure fluid going to the motors inlet channel 48 will then be by-passed around the valvetll so that no differential high pressure of the fluid will be built up. The vane slot ports 48 will be'supplied with fluid under substantially the same pressure as that of the operating pressure fluid entering the fluid inlet areas 29, thus eflecting balance of the hydraulic forces acting in a radial direction upon the vanes l9 when their outer ends are exposed to operating pressure fluid and holding the vanes I9 against the I vane track during the portions of their travel of the valve piston 214 so that said valve piston across the arcs 21 and 3| when their outer ends are exposed to fluid under substantially no pressure.

This arrangement, therefore, providesdiffere'ntial high pressure fluid for the inner ends of the vanes during operation of the motor at relatively low speeds at which centrifugal force alone is not suflicient to produce proper track-following vane action and automatically eliminates this differential high pressure at the relatively high speeds of the motor at which it is not needed.

The fluid motor of the present invention is capable of numerous other modifications such as, for example, the arrangement shown in Fig. ll-which illustrates one of several methods by Y which the direction of'rotation ofthe assembly and oa s driven shaft may bereversed at will. The fluid motor of this embodiment 1s answer amxrorgmding'mevmmmmaauout identical with that shown in Figs} 2; 3 an d '1 except that two end plates of the .ry e- .ums-

trated in Fig. 8 are employed.

The directionof rotation :of the driven shaft movement, the outer ends of the wane! subject-to the working pressime of the fluid with- ,i n the working and means tor sup-- plying to the inner ends of the vanes fluid under pressure" correlated to andhigher than the pres- 7 sure in theworklng chamber, thereby urgin the 22 and of the rotary assembly is reversed byz-j': the conventionalmethod of reversing the direction of fluid flow. For this purpose the circuit is modified to include 'a conventional reversing valve 390 through which operating pressure fluid from the valve 80 will pass into the pipe 342.

whenflsaid reversing valves'rotatable body "I is in the position illustrated in Fig. 11. The pipe 34! connects with the channel 40 of the fluidmotor so that thefluld areas 29 will be the inlet areas and the rotor anddrlven shaft 22 will be driven in a clockwise direction asviewedin Fig. 3.

Fluid exhausted by the motor through the channel ll will pass out through the pipe 343, the

reversing valve 390 and the exhaust pipe 392.-

Direction of fluid flow between the reversing valve and fluid motor will be reversed when the rotatablebody 39! is rotated 90 in a clockwise direction by a suitable means, not shown. Operating pressure fluid from the valve 60 will then vanes-into contact with the track independently oi the action of centrifugal force, said means comprising a supply line, a power connection l therefrom to the working chamber, a'

{pressure connection leading from the supply line to the inner ends of the :vanes and a valve in the power connection; arranged tovmaintain a substantially constant differential pressure in the I connection below the pressure in the suppower 7 grime cithepressureinthesupply i 3. Ina vanetype fluldmotor having a rotor including a plurality of vanes movable inwardly andoutwardly thereof, a casing therefor including a plurality of'fluid sections, each fluid section comprising a working chamber and fluid inlet and outlet chambers on eitherside thereof adjacent. therotor, each workim cham- I ber' extending for an arcuate distance substantially equalto the distance between two adlaoent pass into the pipe 343, the channel It and the fluid areas 30 (which will then be the inlet areas) and will act to drive the rotor and shaft'flin,

a counter-clockwise direction as viewed in Fig, 3, Fluid will be exhausted fromthe areas 28. (which will then be the outlet areas) through the channel 4B and the'pipe I42 which'will then be connected through the reversing valve 380 with the exhaust pipe 352. Y 7

Differential high pressure fluid will be supplied continuously to the inner ends of all the vanes through the pipe 52, regardless of the direction of rotation of the rotor and shaft'22.

It will be understood thatthe embodiments of the invention described herein are merely for while r:v;:- inwardly while through the outlet cham-v vanes, tracks for "guiding the vanes outwardly g through said inlet chambers and hers, the outer ends oi the vanes being subjected to the pressure of the fluid within said respective inlet and outlet chambers as they pass therethrough, and means for supplying to the inner ends of the vanes throughout their rota- Ition fluid underpressure greater than and correlated to the highest pressure within any of said f inlet and outlet chambers thereby continually the purpose of illustrating the invention, and

"that changes may be made without departing from the spirit of the invention, the scope of which is defined in the appended claims.

I Claim: i V 1. In a rotaryvane type fluid pressure device urging'the vanes into contact with the track independently .of the action of centrifugal force,- said means comprising a supply line, a power connection-leading therefrom to the working chamber, a pressure connection leading from the a supply line to the inner ends of the vanes, and a valve'in'the power connection arranged to maintain a substantially constant diflerential having a rotor including a plurality of vanes movable inwardly and outwardly thereof, a casing therefor including a working chamber and a track for guiding the movement, the outer ends of the vanes being within the working chamber, and means for supplying to the inner ends of the vanes fluid under pressure higher than the pressure in the working chamber thereby urging the vanes into contact with the track independently of theaction of centrifugal force, said means comprising a supply line, a power connection leading therefrom to the working chamber, a pressure vanes in their in and out subject to the working pressure of the fluid Jacent the rotor whereby the outer ends of the within the inlet and outlet chambers as they pass therethrough, means for equalizing the connection leading from the supply line to the inner ends of the vanes, and a valve in the power ing therefor including a working chamber and pressure in the power connection below the pressure in the supply line irrespective of the pressure in the supply line.

4. In a rotary vane type fluid pressure device having a rotor including a plurality of vanes movable inwardly and outwardly thereof, 9. casing therefor including a track for' guiding the vanesin their in and out. movement and provided with fluid inlet and outlet chambers ad-'- vanes are subjected, to the pressure of the fluid fluid pressure acting on the opposite ends of the vanes which are passing, through one of said chambers; and means for'supplying to the inner ends, of the vanes which are passing through the other of said chambers fluid under pressure higher than and correlated to the pressure of the fluid acting on the outer ends of said vanes,

said means comprising a supply line, a power connection leading therefrom to the working chamber, a pressure connection leading from the supply line to the inner ends of the vanes, and a valve in the power connection arranged to cut oil communication between thesupply line and the working chamber when the motoris not operating and arranged to establish such communication only after a predetermined differwhile passing therethrough, an; auxiliary pump,

bers adjacent the rotor, the outer ends of the vanes being subject to the pressure of the fluid within said chambers as they pass therethrough, means for equalizing the fluid pressure acting on the opposite ends of the vanes while passing, .through the low pressure chamber, and means for suppling to the inner ends of the vanes during substantially the remainder of their rotary travel fluid under pressure higher than and correlated'to the pressure of the fluid acting on the outer ends of said vanes, said means comprising a supply line, a power connection leading therefrom to the working chamber, a pressure connection leading from the supply line to the inner ends of the vanes, and a valve in the'power connection arranged to maintain a substantially constant differential pressure in the power connection below the pressure in the supply line irrespective of the pressure in the supply line.

6. In a rotary vane type fluid pressure device having a rotor including a plurality of vanes movable inwardly and outwardly thereof, a casing therefor including a track for guiding the vanes in their in and out movement and pro-v vided with two diametrically opposedworking chambers, each having high and low pressure chambers on opposite circumferential sides thereof adjacent the rotor, the outer ends of said the outer ends of said vanes being subject to the respectivepressures within said chambers means connecting the outlet of said pump to the inner ends of the vanes during at least the por-- tion of their rotary travel in which the vanes are moving outward, the pump delivering pressure fluid at a pressure greater than the pressure in the high pressure chamber and in excess of the amount necessary to insure outward movement of the vanes into contact with said track, outlet means for said excess fluid, and means regulating the passage of the excess fluid through theoutlet means to maintain the fluid supplied to the inner ends of the vanes by said a pump at a pressure greater than and having a substantially constant relationshiptothe pressure existing in said high pressure chamber, irrespective of changes in pressure of the fluid in said high pressure chamber.

9. The combination of a rotary vane type fluid pressure device having a rotor including a plurality of vanes movable inwardly and outwardly thereof, a casing therefor including a track for guiding the vanes in their in and out movement and provided with 'a working chamber having high and low pressure chambers on opposite circumferential sides thereof adjacent the rotor, the outer ends of said vanes being subject to the respective pressures within said chambers while passing therethrough, a pressure fluid line vanes being subject to the respective pressures within said chambers while passing therethrough, means for supplying to the inner ends of said vanes during substantially their entire passage through the high pressure and working chambers fluid under pressure greater than and correlated to the pressure of the fluid in said chambers, and means for equalizing the pressure on the. opposite ends of said vanes while passing through the low pressure chamber.

7. The combination of a rotary vane type fluid pressure motor having a rotor including, a

plurality of vanes movable inwardly and out- 1 wardly thereof, a casing therefor including a track for guiding the vanes in their in and out movement and provided with a working chamber having inlet and outlet chambers on opposite cir-- cumferential sidesthereof adjacent the rotor,

f the outer ends of said vane sbeing subject to the respective pressures within said chambers while passing therethrough, a source of fluid under pressure, means for connecting said source with i the inner ends of the vanes during at least a portion of each revolution of the rotor, means 1 including a pressure reducing valve for connecting said source with said inlet chamber, a by- 1 pass valve for the reducing valve andspeedresponsive means operated by the motor for 1 opening the by-pass valve when the motor is 1 operating above a predetermined speed.

8. The combination of a rotary vane type fluid i pressure device having a rotor including a plu- 1 rality of vanes movable inwardly and outwardly thereof, a casing thereforaincluding a track for guiding the wines in their inand out movement 3 and provided with a working chamberhaving high and low pressure chambers on opposite circumferential sides thereof adjacent the rotor,

are passing through said high pressure chamber, 7

and a pressure valve means connected to return excess fluid delivered by said pump to said line and to maintain the fluidsupply to the inner ends of said vanes at a pressure greater than but correlated to the pressure of the fluid in said line.

10. In a rotary vane type fluid motor having a rotor including a plurality of vanes radially movable inwardly thereof, a casing therefor including a track for guiding the vanes in their in and out movement and provided with two diametrically opposed sealing arcs and two diametrically opposed working chambers each having high and low pressure chambers on opposite circumferential sides'thereof adjacent the rotor,

said sealing arcs and working chambers each a tire time that the outer ends thereof are traversing the sealing arcsand the high pressure and working chambers fluid under pressure greater than but correlated to the pressure of the fluid in said high pressure chambers.

11. The combination of a rotary vane type fluid pressure device having a rotor including a plurality of vanes movable inwardly and outwardly thereof, a casing therefor including a track for guiding the vanes in their in and out movement and provided with a working chamber having high and low pressure chambers on opposite circumferential sides thereof adjacent the rotor, the outer ends 'of said vanes being subber.

chamber, a source of pressure fluid under a pressure greater than said first mentioned source of pressure fluid connec'ted'to the inner ends of said vanes during at least a portion of each rotation of the rotor and means for maintaining said fluid of greater pressure connected to the inner ends of said vanes at a pressure correlated to the pressure of the fluid in said high pressure chaml2. In a rotary vane type fluid pressure device having a plurality of fluid sections, each fluid section comprising a working chamber and high and low pressure chambers on the opposaid fluid sections, the other of said casing members having passages for supplying'fluid to the inner ends of said vanes, and means for maintaining fluid in the passages of said other casing member at a pressure related to but greater than the pressure of the fluid in said high pressure chambers.

13. In a rotary vane type fluid pressure device having a plurality of fluid sections, each fluid section comprising a working chamber and high and low pressure chambers on the opposite circumferential sides thereof, a two-part casing comprising axially sepa'rable casing members, a cavity in one of said casing members closed by the other casing member, a rotor positioned in said cavity and having a plurality of vanes movable radially inward and outward thereof, the outer ends of said vanes being subject to the respective pressures within said chambers while passing therethrough, a vane track for guiding sections, the other of said casing members" having passages for supplying fluid to the inner ends of said vanes while the outer ends of the vanes are passing through the high pressure and working chambers of each of said fluid sections, and means for maintaining fluid in the passages of said other casing member at a pressure related to but greater than the pressure of the fluid in said high pressure chambers.

14. In a rotary vane type fluid motor having a rotor including a plurality of vanes movable inwardly and outwardly thereof in a substantially radial direction, a casing therefor including a track for guiding the vanes in their in and out movement and provided with a plurality of working chambers each having high and low pressure chambers on opposite circumferential sides thereof adjacent the rotor, the outer ends of said vanes being subject to the respective pressures within said chambers while passing therethrough, means at one of the axial sides of said rotor for admitting pressure fluid to said high pressure chambers, and means at the other axial side of said rotor only for supplying to the inner ends of said vanes fluid under pressure greater than but correlated to the pressure of the fluid in said high pressure chambers.

15. In a rotary vane type fluid pressure device having a rotor including a plurality of vanes movable inwardly and outwardly thereof, a casing therefor including a working chamber having high and low pressure chambers on opposite circumferential sides thereof, a track for guiding the vanes in their in fiid out movement, the

outer ends of the vanes being subject to the respective pressures of the fluid within said chambers while passing therethrough, and means for continuously supplying to the inner ends of the vanes during substantially the entire time that the outer ends thereof are traversing the high pressure and working chambers fluid under pressure higher than the pressure in the high pressure chamber thereby urging the vanes into contact with the track independently of the action of centrifugal force, said means comprising a supply line, a power connection leading therefrom to the working chamber, a pressure connection leading from the supply line to the inner ends of the vanes, and. a valve in the power connection arranged to cut off communication between the supply line and the working chamber when the motor is not operating and arranged to establish such communication only after a predetermined difference in pressure exists between the supply line and the working chamber.

16. In a rotary vane type fluid pressure device having a rotor including a plurality of vanes movable inwardly and outwardly thereof, a casing therefor including a working chamber having inlet and outlet chambers on opposite circumferential sides thereof and a track for guiding the vanes in their in and out movement, said working chamber extending for an arcuate distance substantially equal to but not less than thedistance between two adjacent vanes, the outer ends of the vanes being subject to the respective pressures of the fluid within said chambers while passing therethrough, and means for continuously supplying to the inner ends of the vanes while they are traversing the inlet chamber fluid under pressure correlated to and higher than the pressure in the inlet chamber, thereby urging the vanes into contact with the track independently of the action of centrifugal force, said means comprising a'supply line, a supply connection leading therefrom to the inlet chamber, a pressure connection leading from the supply line to the inner ends of the vanes, and a valve in the supply connection arranged to maintain a substantially constant differential pressure in the supply connection below the pressure in the supply line irrespective of the pressure in the supply line.

1'7. In a rotary vane type fluid pressure motor having a rotor including a plurality of vanes movable inwardlyand outwardly thereof, a casing therefor including a sealing chamber, a workunder pressure correlated .to and higherthan 1 the pressure in the inlet-chamber, thereby urg- 'ing the vanes into contact with the track independently of the action of centrifugal force, said 1 means comprising a supply line, a power connec- 5 tion leading therefrom to the working chamber, a pressure connection leading from the supply 1 line to the inner ends of the vanes, and. a valve in the power connection arranged to maintain a substantially constant differential pressure in the power connection below the pressure in' the supply line irrespective of the pressure in the supply line, said valve also being arranged to cut I ofl communication between the supply line and the working chamber when the motor is not 1 operating and arranged to establish such communication only after a predetermined difference -1 in pressure exists between the supply line and the working chamber.

18. The combination of a rotary vane type fluid 1 pressure device having a rotor including a plurality of vanes movable inwardly and outwardly 3 thereof, a casing therefor including a track for guiding the vanes in their in and out movement 1 and provided with a working chamber having 1 inlet and outlet chambers on opposite circum- 5 ferential sides thereof adjacent the rotor, the outer ends of said vanes being subject to the re- ;spective pressures within said chambers while i passing therethrough, an auxiliary pump, means 1 connecting the outlet of said pump to the inner ends of said vanes during at least the time that the outer ends of the vanes are passing through 1 said inlet chamber, said pump delivering fluid in excess of the amount necessary to insure outward movement of said vanes into contact with said 1 track, and escape means for said excess fluid including means regulating the escape of said 5 excess therethrough to maintain the fluid supand outlet chambers respectively, an auxiliary pump arranged to supply pressure fluid to the inlet ports, means regulating the pressure of the fluid supplied by the pump to maintain in theinlet ports a pressure exceeding by a substantially constant amount the pressure of the fluid in the inlet chambers irrespective of changes in pressure of the fluid in the inlet chambers, and fluid outlet means for the outlet ports.

20. A rotary vane type fluid motor including a rotor, a plurality of vanes movable inwardly and outwardly of the rotor, a casing for the rotor having a track for guiding the vanes in their in and out movement and provided with two diametrically opposed sealing arcs and two diametrically opposed working chambers each having high and low pressure chambers on opposite circumferential sides thereof adjacent the rotor, said sealing arcs and working chambers each extending for an arcuate distance substantially equal to but not less than the distance between two adjacent vanes, the outer ends of jthe vanes being subject to the respective pressures within said chambers while passing therethrough, means for substantially equalizing the pressure of the fluid on the inner and outer ends of the vanes while the outer ends of the vanes are passing through the low pres sure chambers, and means for supplying to the inner ends'of the vanes while the outer ends thereof are passing through the high pressure chambers fluid under pressure greater than but correlated to the pressure of the fluid in the high pressure chambers, said last named means including an auxiliary pump arranged to provide the fluid of greater pressure.

' CHARLES M. KENDRICK. 

